Tubing anchors are used for various purposes but mainly to hold strings of tubing in cased wellbores and more specifically to assist in maintaining tubing in tension. They are typically used in conjunction with well equipment particularly reciprocating rod pumps. The tubing anchor sets one or more slips against the well conduit usually well casing to grip the well conduit. The tubing may then be held in tension limiting its movement. Tubing anchor catchers perform these functions but also, should tubing string above the anchor catcher unthread or break the tubing anchor catcher provides a means to grip against the well conduit. For the purposes of the present invention these two general categories of tools are herein referred to collectively as “tubing anchoring tools”.
As it is run into the well the tubing string often also has to carry different types of lines and cables downhole, including capillary lines and cables and other lines known to persons of skill in the art typically down to an intake section of the pump. For the purposes of the present invention such lines and cables can be referred to as “cable” or “cables”. Once set, cable must remain positioned along the tubing string including running past tubing anchoring tools.
Running cables along such tubing strings past tubing anchoring tools may be difficult as there may be very little annular space between the tubing string and the wellbore casing. This is particularly true in casings with smaller inside diameters (ID's).
Furthermore, most prior art tubing anchoring tools often require multiple full (i.e. several 360 degree) rotations of the mandrel to either set or unset the tubing catcher. These are often called multi-rotation tools. Multi-rotation tools may either be threaded for multiple rotations, such as for example U.S. Pat. No. 3,077,933 to Bigelow, or may comprise a helical bearing track to provide multiple rotations, such as for example U.S. Pat. No. 5,771,969 to Garay. For purposes of the present invention such tools can be referred to as “multi-rotation anchoring tools”.
In using multi-rotation anchoring tools where cable is installed in the well, extra cable has to be provided which cable is there to be used up in the setting of the multi-rotation tool (as the mandrel of the tool is rotated via rotating the tubing string from surface the extra cable becomes wrapped around the tubing string). Alternately the extra cable is originally pre-wrapped in an opposite direction to the direction of mandrel rotation and then when the tubing string and mandrel are rotated such extra cable unwinds leaving loose cable around the tubing string. In addition to the preceding difficulties with cable in using multi-rotation tools, multi-rotation tools are sometimes not preferred for narrow or deviated well conduits in which there is no room to accommodate multiple rotations of the tubing string to set or unset a tubing anchoring tool, and there are the additional, preceding concerns with the use of cables with multi-rotation anchoring tools.
More recently tubing anchor catchers and tubing anchors that are set by turning their mandrels only a portion of a full rotation preferably by only a quarter or one third rotation or turn of their mandrels, by means including a pin and slot arrangement within the drag body and mandrel respectively, have been invented and employed for this purpose. The only known such quarter turn anchoring tools are described in Applicant's Canadian application number 2,890,533 or US patent publication number 2015/0233199A1, or Applicant's Canadian application number 2,798,833. For the purposes of the present invention such tools can be referred to collectively as “quarter turn anchoring tools”. The actuation of quarter turn anchoring tools obviously does away with certain of the challenges of multi-rotation anchoring tools that were described preceding.
Quarter turn anchoring tools (and multi-rotation anchoring tools) comprise a slip retainer or slip cage for housing slips to grip the well conduit. These slip cages are made of a single integral pipe or tube of metal with windows formed therein to accommodate the slips. Similarly, the drag bodies holding the drag blocks are also made from a separate, single integral piece of pipe or tubular metal.
As described in the preceding-mentioned patent applications and above, such quarter turn tubing anchoring tools are preferably used in wellbores where the annular space between the outside of the slip cage and drag block on the one hand, and the inside of the well conduit on the other, is small. Such space may be too small for usual cables to fit in between particularly slip cage outer diameters (OD's) and casing ID's. But such tools are not seemingly adaptable to accommodating a gap or break in the slip cage and drag body to locate a place for accommodating cable to be run past them, given the respective problems namely the slip cages and drag bodies are unitary in nature and should remain so to better enable them to withstand multiple significant forces particularly when the slips are actuated, and given the smaller spaces for such cable between slips and blocks.
Running cables inside of portions of tubing anchoring tools has been tried but has led to problems including the expected movement and function interference where cables come into contact with portions of slips drag blocks or other internal parts.
Therefore the need to accommodate running cable past tubing anchoring tools of both a multi-rotational anchoring tool kind, and in particular for quarter turn anchoring tools, still arises. For the purposes of the present invention such anchoring tools may be collectively referred to as “tubing anchoring tools”.